1. Field of the Invention
The present invention relates, in general, to frozen dairy products. More particularly, the present invention relates to formulations and methods for producing frozen dairy products for dessert use that have surprising stability, organoleptic, and body characteristics.
2. Statement of the Problem
Frozen dairy products enjoy great popularity. Many variations of frozen dairy products have been developed for dessert use, including ice cream, whipped toppings, and soft-serve products. Soft-serve products are particularly popular and have a wide appeal. Distinguishing features of conventional soft serve products are that they are frozen in a special soft-serve freezer, are dispensed by extrusion at carefully chosen subfreezing temperatures, and generally stand up on a cone or dish upon extrusion. Conventional soft-serve products are usually dispensed at an overrun on the order of 40% to 60%. Although soft-serve products of this character have been marketed for many years, they are still available only from stores having special freezers that dispense the product for immediate consumption. This is because the product generally is dispensed at temperatures between 16xc2x0 F. and 24xc2x0 F. At lower temperatures, the product is no longer sufficiently soft. Thus, conventional soft-serve products are not suited for sale from grocery store freezers for home storage and use. Home freezers maintain temperatures generally around 0xc2x0 F. to 10xc2x0 F., and store freezers, which as used herein includes grocery store, supermarket, and restaurant freezers, are generally at colder temperatures. Others have expended considerable effort to develop a soft-serve product for home use, but apparently with little success. A search of the prior art concerning such frozen dairy products discovered the following patents:
PCT Patent No. WO 97/30600 to Rivixc3xa8re et al. teaches a compound that is xe2x80x9cspoonablexe2x80x9d at xe2x88x9218xc2x0 C. to xe2x88x9224xc2x0 C. (xe2x88x920.4xc2x0 F. to xe2x88x9211.2xc2x0 F.) and that contains 6 to 18 wt % milk proteins (as skim milk or dried milk powders), 6 to 24 wt % fat, 20.3 to 24.6 wt % carbohydrates (8.2 to 13.3 wt % dextrose, 3.3 to 8.2 wt % invert sugar, and 7.0 to 8.2 wt % glucose syrup), 0.25 to 0.8 wt % stabilizer, and 49 wt % liquid skim milk. The overrun is 50 to 200%. The Rivixc3xa8re patent relies on vegetable fat with a very low melting point, specifically sunflower oil, to achieve the softness or spoonability set forth. There is a further reliance on the use of emulsifiers (mono- and diglycerides) to provide the whipability, desirable texture, and shelf life characteristics of this frozen dessert.
U.S. Pat. Nos. 4,346,120 and 4,400,406 to Morley et al. teach a soft-serve compound. U.S. Pat. No. 4,346,120 shows a compound with 5 to 15 wt % milk solids non-fat (MSNF), 5 to 15 wt % fat, 20 to 40 wt % carbohydrates, 0.25 to 1.3 wt % stabilizer, 0.2 to 0.8 wt % emulsifier, and 43 to 65 wt % water. The overrun is between 110 and 220%. U.S. Pat. No. 4,400,406 is a continuation in part of the U.S. Pat. No. 4,346,120 patent that has different ranges: protein is between 3 and 7 wt %, fat is at 3 to 15 wt %, carbohydrates are at 18 to 30 wt %, stabilizer is at 0.35 to 1.0 wt %, water is at 43 to 65 wt %, and emulsifier is at 0.2 to 0.8 wt %. The overrun is between 100 and 220%. The Morley patent relies upon providing a saccharide system containing various sugars, a stabilizer system employing at least one stabilizer from each of at least three groups of stabilizers, and an emulsifier system having particular emulsifiers to provide an extrudable product at home freezer temperatures (0xc2x0 F. to 10xc2x0 F.). The carbohydrates used include fructose, sorbitol (a sugar alcohol), and corn syrup. The presence of the sorbitol is justified by a need to compensate for the excessive sugary taste imparted by the fructose.
U.S. Pat. No. 5,482,728 (to Tapfer et al.) teaches xe2x80x9chardxe2x80x9d ice cream compositions containing 10 to 12.19 wt % MSNF, 5 to 14 wt % milk fat, 12.99 to 18.48 wt % carbohydrates as sugars encapsulated in fat, 0.29 to 0.34 wt % stabilizer/emulsifier, and 58.28 to 69.48 wt % water. The overrun is 50%. The key to the Tapfer et al. results is their method in which the sugar components are encapsulated in fat before use.
U.S. Pat. No. 5,690,983 (to Sponholtz) discloses an unfrozen expanded ice cream mix having 10.70 wt % MSNF, 8.00 wt % milk fat, 8.00 wt % sucrose, 7.0 wt % dextrose, 2.55 wt % stabilizer-emulsifier mix (Mixture TS-D 434), and 4.5 wt % flavor, for a total solids content of 42.75 wt %. The composition forms a liquid aerated mix with an overrun of 90% that can be stored at non-freezing temperatures.
U.S. Pat. No. 4,452,824 (to Cole et al.) teaches a soft-serve composition containing 2 to 10 wt % MSNF, 2 to 15 wt % milk fat, 24 to 34 wt % carbohydrates, 0 to 2 wt % stabilizer, 0.2 to 1.0 wt % emulsifier, and 45 to 65 wt % water. The carbohydrates are distributed in a critical combination so that the ratio of higher saccharides to mono- and disaccharides (ratio 1) and the ratio of disaccharides to monosaccharides (ratio 2) satisfy the relationship of 11xe2x89xa6(28xc3x97ratio 1)+ratio 2xe2x89xa628. The overrun is 50 to 200%.
U.S. Pat. No. 4,478,867 (to Zobel et al.) teaches a process for whipping an emulsion. The emulsion contains 2 to 30 wt % nonfat dry milk, 18.0 to 30.0 wt % vegetable fat, 20.0 to 30.0 wt % carbohydrates, 0.01 to 2.0 wt % stabilizer, 0.5 to 2 wt % sodium caseinate, 0.4 to 2.0 wt % emulsifier, and 40 to 60 wt % water. The overrun is 200 to 350%. This emulsion has a texture similar to that of whipped cream (Cool Whip(copyright)).
U.S. Pat. No. 5,077,076 (to Gonsalves) teaches a formula for a whipped topping. The topping is comprised of 2.5 to 7.0 wt % MSNF, 5 to 15 wt % fat (either vegetable fat or milk fat), 15 to 25 wt % carbohydrates, 0.05 to 1.0 wt % stabilizer, 0.5 to 2 wt % sodium caseinate, 0.15 to 0.6 wt % emulsifier, 0.03 to 0.15 wt % phosphate salts, and 57 to 62 wt % water. The overrun is more than 250%. This topping also has a texture similar to that of whipped cream (Cool Whip(copyright)).
U.S. Pat. No. 5,171,602 (to Martin et al.) discloses a nonfat composition for a dessert product consisting of 8 to 18 wt % MSNF, 12 to 36 wt % carbohydrates, 0.5 to 3.0 wt % starch, and the balance being water. There is no fat, stabilizer, or emulsifier. The overrun is 80 to 100%.
U.S. Pat. No. 5,358,728 (to Martin et al.) is similar to U.S. Pat. No. 5,171,602, except that 0.03 to 0.3 wt % polyphosphate compounds are added.
U.S. Pat. No. 4,421,778 (to Kahn et al.) teaches compounds that contain a premix comprising 10 to 30 wt % fat, 3.5 to 20 wt % emulsifier, 6 to 34 wt % stabilizer, and the balance being a protein carrier, such as MSNF, dairy whey, whey protein, and/or a carbohydrate carrier. The basic composition is described as an oil-in-water emulsion of 3.00 wt % premix, 10.85 wt % protein, 24.00 wt % carbohydrates, 54.24 wt % water, 0.50 wt % flavor, and 7.41 wt % fat, of which at least 50% is a solid beta phase-tending crystalline fat (such as lauric fats, coconut oil, palm kernel oil, palm oil, etc.) that prevents the formation of crystalline surfaces. The overrun is 70 to 130%.
U.S. Pat. No. 4,840,813 (to Greenberg et al.) discloses a product having 4.0 to 7.2 wt % casein and 1 to 7 wt % whey. It is required by this patent to have a whey:casein ratio from 1:0.5 to 1:4. The product also includes 0.1 to 9.0 wt % fat, 14 to 18 wt % carbohydrates, 0.5 to 2 wt % ash, 0.1 to 5.0 wt % flavor, and 55 to 65 wt % water. The overrun is 40 to 100%.
In these prior formulations, it has been common to obtain a soft-serve type of product by the use of sugar alcohols, emulsifiers, vegetable fats, and other additives, all of which may add undesirable tastes or mouth sensations to the frozen dairy product. In other formulations, a soft-serve type of product has only been obtainable through the use of complex formulations and ratios of ingredients, or by complicated methods. To achieve different flavors or different types of products, additional ingredients must be added. None of the above references has provided a product having commercial success as a soft-serve ice cream type of product for home use.
The present invention is directed to frozen dairy products having desirable texture and that are soft and scoopable at home freezer temperatures (that is, at about 0xc2x0 F. to about 5xc2x0 F.) with unique organoleptic properties. The present invention also provides frozen dairy products that have a long shelf-life and that have an overrun of about 200%. In addition, the present invention provides for different embodiments of frozen dairy products, such as yogurt-like and custard-like. All of these characteristics are obtained by the present invention with simple and straightforward formulations that do not include sugar alcohols or vegetable fats. Further, emulsifiers may or may not be used, and preferably are not used in the present invention.
The frozen dairy product of the present invention is formulated with ingredients that provide fat, protein, water, sweeteners, and stabilizer constituents in a combination that permits the attainment of the desirable properties described above. The attainment with these ingredients of these properties is deemed unexpected and not predictable.
The frozen dairy product of the present invention preferably comprises, on a weight basis, about 10% to about 13% milk solids non-fat (MSNF), about 4% to about 16% milk fat, about 5% to about 10% sucrose, about 2% to about 8% corn syrup having a DE of about 36, about 4% to about 12% dextrose, about 0% to about 1.5% starch, and about 0.2% to about 1.0% stabilizer.
One particular feature of the frozen dairy products of the present invention is the ability to be aerated with significantly more air than is common for frozen dessert products. In the ice cream and soft serve industries, the amount of air in a product is described as xe2x80x9coverrun.xe2x80x9d Overrun measures the percentage by which the volume of the liquid mix for a product is increased with air during whipping and freezing. The overrun of the frozen dairy product of the present invention is about 200%. It is unexpected for the formulation of this product to be able to attain such an overrun and produce a product with satisfactory shelf life/stability.
A method for production of the frozen dairy products is also provided by the present invention. In this method, a first mixture is prepared by adding the sucrose, corn syrup, dextrose, starch (if used), and stabilizer to heated water with agitation. The milk fat and milk solids non-fat are then added to the first mixture to form a final mixture. The final mixture is agitated for a time to thoroughly mix the ingredients. The final mixture is then pasteurized and homogenized. After these steps, the final mixture is aerated to an overrun of about 200% in a scrape surface heat exchanger, extruded, and packaged by conventional methods. The packaged mixture is then hardened for a predetermined period of time at xe2x88x9230xc2x0 F. Unlike previous methods for producing frozen dessert products, there is no xe2x80x9cmix maturationxe2x80x9d step.
Accordingly, it is an object of the present invention to provide frozen dairy products having a desirable texture and unique organoleptic properties. It is another object of the present invention to provide frozen dairy products that are soft and scoopable at about 0xc2x0 F. to about 5xc2x0 F. It is an object of the present invention to provide frozen dairy products that can be produced in both regular and low-fat formulations and in a variety of product types without the addition of separate flavor ingredients. It is a further object of the present invention to provide methods for producing frozen dairy products.
These and other advantages, features, and objects of the present invention will be more readily understood in view of the following detailed description.
The present invention provides frozen dairy products that are soft and scoopable at about 0xc2x0 F. to about 5xc2x0 F., have a stable through shelf-life, and incorporate a significant amount of air (up to about 200% overrun) while also having unique (creamy) organoleptic properties. Methods of production for the frozen dairy products are also disclosed herein. The frozen dairy products can be produced by the methods in a variety of embodiments, such as ice cream-like, low-fat ice cream-like, low-fat yogurt-like, and custard-like. Each of these embodiments can be further flavored, for example, with cocoa or other liquid flavor ingredients, or can support the addition of other edible materials, such as fruit, nuts, or candy pieces, for example.
Throughout the specification and claims, percentages and ratios are by weight and temperatures are in degrees Fahrenheit unless otherwise indicated.
The frozen dairy products of the present invention generally contain milk solids non-fat, milk fat, sucrose, corn syrup having a DE of about 36, dextrose, and stabilizer. In some embodiments, starch is present in the formulation. The amount and exact character of each ingredient will depend upon such factors as the character of the other ingredients and the desired nature of the end product. For example, the amount of fat is varied to provide regular and low-fat frozen dairy products. In one embodiment, a soft textured ice creamlike product is provided. In another embodiment, the milk solids non-fat are cultured with bacteria to a predetermined acidity, which provides a frozen yogurt-like product. In a further embodiment, egg yolk is added to provide a frozen custard-like product.
In an important embodiment, the composition of the present invention that can be used to prepare frozen dairy products generally has the following components as set forth in Table I.
Milk solids non-fat as used in the preferred compositions of this invention can be derived from cream, milk (including condensed milk, skim milk, and condensed skim milk), and non-fat dry milk. Milk solids non-fat aid in providing the desirable properties of whipability, smoothness, body, mouthfeel, and melt resistance.
The milk fat ingredient aids in providing a creamy taste and the eating characteristics associated with ice cream-like products. It also contributes to the smoothness, the body, and the melting resistance of the frozen dairy products. Dairy cream and milk are the preferred fat sources.
The sweetener ingredients preferably are a combination of sucrose, dextrose, and corn syrup that provide a desired level of sweetness and texture to the frozen dairy products. The combination of dextrose, sucrose, and corn syrup also serves to decrease the freezing point of the mixture. It is postulated that the freezing point depression decreases viscosity, thus allowing for uniform and stable incorporation of air. The corn syrup preferably has a dextrose equivalent (DE) of about 36, which is in the low DE range of corn syrups. Corn syrups possessing a DE of about 24 to about 42 can be used in this invention. Corn syrup of 36 DE is preferred for ease of processability and satisfactory low-molecular-weight sugar composition. In addition, high-fructose corn syrup can be used.
The stabilizer ingredient may also contribute to the attainment of the desired features of the new frozen dairy products. The stabilizer ingredient is used to improve the ability of the products to withstand commercial shelf life and substantial heat shock without undue deterioration, such as a loss of overrun. The stabilizer ingredient may include vegetable gums and, in a preferred embodiment, the stabilizer ingredient is selected from the group consisting of locust bean gum, guar gum, and carrageenan. Other stabilizers may be appropriate for use in the present invention, and such stabilizers will be evident to those skilled in the art and are meant to be included in this description of the frozen dairy products.
Water is present in the new frozen dairy products as a dispersion medium for the other ingredients of the emulsified product. The portion of water in the product is determined on an xe2x80x9cas neededxe2x80x9d (q.s.) basis to provide the balance of the mixture with reference to a total weight of 100% after the weights of the other ingredients are taken into account. The portion of water in the products that remains unfrozen provides fluidity for the product. The portion of water that does freeze forms ice crystals that give the product rigidity as well as the refreshing taste perception characteristic of a frozen dessert.
A flavor ingredient can be added to these ingredients if desired. The flavor ingredient is selected from known flavors according to the desired taste, taking into account the other ingredients. Flavor ingredients include, by way of illustration, liquid flavor ingredients such as vanilla, vanilla extract, cocoa, and mint, and solid flavor ingredients such as fruits, nuts, candy, chocolate- and peanut-flavored chips and the like, as well as other flavor ingredients. The present invention provides frozen dairy products with a stable matrix that will hold unexpectedly large amounts of such flavor ingredients. For example, cocoa is added at up to about 3.5% to provide a chocolate flavor. Fruit and nuts can be added from about 0% to about 40% usage by weight. Note, however, that the ingredient ranges specified herein, unless stated otherwise, are for an unflavored product. Those skilled in the art will comprehend the adjustments appropriate for the particular flavor ingredient used. Of importance to the present invention, different embodiments of the frozen dairy products exist that are not dependent on the addition of flavor ingredients, such as yogurt-like or custard-like products (see examples below).
In addition to the foregoing ingredients, the frozen dairy products of the present invention can include other ingredients if desired, such as, for example, starches. If starches are used in the formulations of the present invention, any modified food starch, such as, for example, corn starch, potato starch, rice starch, or tapioca starch, can be used. The starch used in the compositions of the present invention is preferably modified corn starch. Modified starches, when used at low levels (less than about 2%), offer improved texture (creaminess) and improved shelf-life (stability) to the frozen dairy products. It is thought that starch molecules organize water in fashion similar to that of hydrocolloid (stabilizer) molecules by obstructing ice crystal growth and/or changing the morphology of ice crystals. In addition, starch may enhance the whipability and air incorporation in the frozen dairy products by strengthening the solids matrix surrounding the air cells.
In order to achieve the frozen dairy products of the present invention, a particular method is preferably used. In a preferred method of the present invention, the water required is added to a kettle provided with an agitating device. The preferred agitating device is a Lanco/Breddo(trademark) high shear mixer/liquefier that is preferably operated at its highest speed. The water is heated to a temperature of from about 120xc2x0 F. to about 130xc2x0 F.
The order of addition of the individual ingredients is important to obtain uniform blending of the ingredients. The following order of addition is preferred. The sucrose, corn syrup, dextrose, stabilizer, and starch (if present) are added to the heated water, and agitation is commenced and continued for a period of from about 30 seconds to about 4 minutes, preferably about 2 minutes, to form a first mixture. The milk fat and milk solids non-fat are then added and agitation is continued for an additional about 30 seconds to about 4 minutes, preferably about 2 minutes, to form a final mixture.
The final mixture is then pasteurized under suitable time and temperature conditions, preferably at a temperature of from about 180xc2x0 F. to about 200xc2x0 F. for a hold time of about 30 to about 120 seconds, followed by regeneration and cooling to about 40xc2x0 F. In another embodiment, the final mixture is pasteurized by vat between about 165xc2x0 F. to about 170xc2x0 F. for about 30 minutes, followed by similar regeneration and cooling to about 40xc2x0 F.
The pasteurized final mixture is then homogenized in a conventional two-stage homogenizer. In a preferred embodiment, homogenization comprises a first stage performed at a pressure of about 500 psi to about 1,500 psi and a second stage following the first stage, with the second stage performed at about 2,000 psi to about 5,000 psi.
After pasteurization and homogenization, the final mixture is flavored, aerated in a scrape surface heat exchanger, extruded, and packaged by conventional methods. The aerated final mixture has an overrun of about 200%. The packaged mixture is then hardened at about xe2x88x9230xc2x0 F. for about 6 hours to about 18 hours before distribution.
Once the frozen dairy products are prepared by the above method, they can be stored for about 2 weeks to about 4 weeks at either store freezer or home freezer temperatures and also resist considerable temperature variations, such as that which occurs between the time the product is purchased from a store until the product is placed in a home freezer, without significant loss of their desirable properties.
Of importance to the present invention, the desired properties of a soft texture that is scoopable at about 0xc2x0 F. to about 5xc2x0 F., unique organoleptic properties, a stable shelf-life, and the ability to hold an overrun of about 200% are obtained in the frozen dairy products of this invention with the use of the above-described ingredients in a straightforward combination and method of production. These results are deemed unexpected and advantageous, in that other ingredients such as emulsifiers, complex ratios of ingredients, and additional, time-consuming steps, such as a mix maturation step in which the product is held at a predetermined temperature for up to 24 hours before freezing, have generally been necessary in previous frozen products in order to achieve some of these desirable results.
The individual ingredients comprising the compositions of the invention may be varied in quantity to obtain embodiments of frozen dairy products having different flavor and textural sensations without the use of additional flavor and textural ingredients as described above. The following examples further illustrate various features of the present invention that are intended to in no way limit the scope of the invention that is defined in the appended claims.